scholarly journals Design Optimization and Application of Hybrid Bit to Reduce a Well Cost in Geothermal Field

2020 ◽  
Vol 9 (1) ◽  
pp. 1-10
Author(s):  
Muhammad Taufiq Fathaddin ◽  
Fakhri Ade Andika ◽  
Ratnayu Sitaresmi
Keyword(s):  
Design Optimization ◽  
Cutting Force ◽  
Sliding Mode ◽  
Lateral Force ◽  
Geothermal Field ◽  
Dynamics Simulation ◽  
Lateral Acceleration ◽  
Average Value ◽  
Fea Modeling ◽  
Drilling Simulation

Hybrid bit is one of the innovations developed for very hard and abrasive formations such as in geothermal field. This bit eliminates the risk of losing cones, reduces tripping time, and increaseas ROP to reduce the well cost. The stage of data processing by calculating the UCS formation using D-BOS software and design optimization based on 9-7/8" bits simulations in granodiorite formations. The 1st phase was to determine the 4 best out of 7 hybrid bit designs that were selected from the highest ROP obtained, the most stable cutter cutting force, and the lowest vibration by comparing the results of FEA modeling of 1 ft drilling simulation. The 2nd phase is to choose 1 of the best from the 4 selected by doing 50 ft of drilling dynamics simulation which is assessed by directional capability, the durability, and the lowest MSE. In this study to improve drilling optimization in geothermal field, it was found that the Z616 hybrid bit design was the most optimal one. Based on 1st phase simulation, this bit was able to produce ROP of 6.38 mph, a stable cutter cutting force, very low average lateral 2.109 g and axial vibration 0.329 g. Furthermore, for the 2nd phase simulation of 50 ft, seen from the comparison of directional capability, this bit has a 0.91 deg/100 ft DLS in rotating mode, and 6.5 deg/100ft DLS in sliding mode means quite stable when drilling in rotary mode and easy to make some angle in slide mode. By its durability, the average value of lateral acceleration is 10 g, and the lateral force is 6 klbf. By MSE side, this bit also produces the lowest average MSE value of 769 psi. From the economic view, this bit can save USD 198,625 - USD 564,712 of a well cost.

ON SHALLOW‐HOLE TEMPERATURE MEASUREMENTS—A TEST STUDY IN THE SALTON SEA GEOTHERMAL FIELD

Geophysics ◽  
1977 ◽  
Vol 42 (3) ◽  
pp. 572-583 ◽  
Author(s):  
Tien‐Chang Lee
Keyword(s):  
Numerical Methods ◽  
Ground Surface ◽  
Nonlinear Least Squares ◽  
Geothermal Gradient ◽  
Geothermal Field ◽  
The Other ◽  
Temperature Measurements ◽  
Salton Sea ◽  
Depth Interval ◽  
Average Value

Shallow‐hole (<13 m) temperature measurements made at various depths and/or times may yield reliable values of geothermal gradient and thermal diffusivity if the groundwater table is shallow (a few meters) such that the effect of time‐dependent moisture content and physical properties is negligible. Two numerical methods based on nonlinear least‐squares curve fitting are derived to remove the effect of annual temperature wave at the ground surface. One method can provide information on the gradient and diffusivity as a function of depth while the other gives average value over the depth interval measured. Experiments were carried in six test holes cased with 2 cm OD PVC pipes in the Salton Sea geothermal field. A set of 5 to 7 thermistors was permanently buried inside the individual pipes with dry sand. Consistent gradient determinations have been obtained with both numerical methods from six monthly observations. By linearly extrapolating the depths to the 100°C and 200°C isotherms from the calculated gradients and mean ground temperatures, we have found good agreement with the nearby deep‐well data for four holes. Discrepancy is found for two holes, one of which is located near the field of [Formula: see text] mud volcanoes and the other near the volcanic Red Hill, reflecting complicated local hydrologic conditions.

scholarly journals Research on Bogie Frame Lateral Instability of High-Speed Railway Vehicle

2018 ◽  
Vol 2018 ◽  
pp. 1-13
Author(s):  
Chen Wang ◽  
Shihui Luo ◽  
Ziqiang Xu ◽  
Chang Gao ◽  
Weihua Ma
Keyword(s):  
High Speed ◽  
Dynamics Simulation ◽  
Lateral Acceleration ◽  
Railway Vehicle ◽  
Lateral Instability ◽  
Bogie Frame ◽  
High Speed Railway ◽  
Long Time ◽  
Line Test ◽  
Equivalent Conicity

In order to find out the reason for the bogie frame instability alarm in the high-speed railway vehicle, the influence of wheel tread profile of the unstable vehicle was investigated. By means of wheel-rail contact analysis and dynamics simulation, the effect of tread wear on the bogie frame lateral stability was studied. The result indicates that the concave wear of tread is gradually aggravated with the increase of operation mileage; meanwhile the wheel-rail equivalent conicity also increases. For the rail which has not been grinded for a long time, the wear of gauge corner and wide-worn zone is relatively severe; the matching equivalent conicity is 0.31-0.4 between the worn rail and the concave-worn-tread wheel set. The equivalent conicity between the grinded rail and the concave-worn tread is below 0.25; the equivalent conicities are always below 0.1 between the reprofiled wheel set and various rails. The result of the line test indicates that the lateral acceleration of bogie frame corresponding to the worn wheel-rail can reach 8.5m/s2, and the acceleration after the grinding is reduced below 4.5m/s2. By dynamics simulation, it turns out that the unreasonable wheel-rail matching relationship is the major cause of the bogie frame lateral alarm. With the tread-concave wear being aggravated, the equivalent conicity of wheel-rail matching constantly increases, which leads to the bogie frame lateral instability and then the frame instability alarm.

scholarly journals Optimization on the Crosswind Stability of Trains Using Neural Network Surrogate Model

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Le Zhang ◽  
Tian Li ◽  
Jiye Zhang ◽  
Ronghuan Piao
Keyword(s):  
Contact Force ◽  
Surrogate Model ◽  
Lateral Force ◽  
Dynamics Simulation ◽  
Load Reduction ◽  
Dynamic Parameters ◽  
Wheel Load ◽  
Running Safety ◽  
Derailment Coefficient ◽  
Safety Metrics

AbstractUnder the influence of crosswinds, the running safety of trains will decrease sharply, so it is necessary to optimize the suspension parameters of trains. This paper studies the dynamic performance of high-speed trains under crosswind conditions, and optimizes the running safety of train. A computational fluid dynamics simulation was used to determine the aerodynamic loads and moments experienced by a train. A series of dynamic models of a train, with different dynamic parameters were constructed, and analyzed, with safety metrics for these being determined. Finally, a surrogate model was built and an optimization algorithm was used upon this surrogate model, to find the minimum possible values for: derailment coefficient, vertical wheel-rail contact force, wheel load reduction ratio, wheel lateral force and overturning coefficient. There were 9 design variables, all associated with the dynamic parameters of the bogie. When the train was running with the speed of 350 km/h, under a crosswind speed of 15 m/s, the benchmark dynamic model performed poorly. The derailment coefficient was 1.31. The vertical wheel-rail contact force was 133.30 kN. The wheel load reduction rate was 0.643. The wheel lateral force was 85.67 kN, and the overturning coefficient was 0.425. After optimization, under the same running conditions, the metrics of the train were 0.268, 100.44 kN, 0.474, 34.36 kN, and 0.421, respectively. This paper show that by combining train aerodynamics, vehicle system dynamics and many-objective optimization theory, a train’s stability can be more comprehensively analyzed, with more safety metrics being considered.

scholarly journals Dynamics simulation of ammonia nitrogen absorption in a rural–urban canal on the Northeast China Plain

2018 ◽  
Vol 78 (3) ◽  
pp. 622-633 ◽  
Author(s):  
Yujia Song ◽  
Xiaodong Wang ◽  
Haiying Zhang
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Absorption Rate ◽  
Ammonia Nitrogen ◽  
Dynamics Simulation ◽  
Background Concentration ◽  
Absorption Length ◽  
Average Value ◽  
Variation Range

Abstract To study dynamic laws of ammonia nitrogen retention in a typical rural–urban fringe canal, NaBr was selected as a conservative tracer agent, and NH4Cl as an additive nutritive salt to conduct an instantaneously added tracer experiment outdoors. On this basis, tracer additions for spiralling curve characterisation (TASCC) method and nutritive spiral indexes were used for the quantitative depiction of retention dynamics of NH4+-N. The Michaelis–Menten (M-M) model was used to simulate absorption dynamic characteristics of NH4+-N. Results showed that the variation range of absorption length of NH4+-N under background concentration was 93.94–295.54 m with an average value of 177.41 m, the variation range of mass transfer coefficient was 0.16–0.38 mm/s with an average value of 0.26 mm/s, and the variation range of absorption rate was 0.16–0.38 mg/(m2⋅s) with an average value of 0.26 mg/(m2⋅s). The maximum absorption rate of NH4+-N obtained via M-M equation simulation was 0.59–1.38 mg/(m2⋅s), and the subsaturation constant was 1.10–5.03 mg/L. The variability of the dynamic absorption length, overall dynamic absorption rate, and overall dynamic mass transfer coefficient shown by NH4+-N within the range from background concentration to saturation concentration certified that TASCC could analyse the dynamic process of NH4+-N retention and absorption by the canal.

scholarly journals Adhesion state estimation based on improved tire brush model

2018 ◽  
Vol 10 (1) ◽  
pp. 168781401774770
Author(s):  
Bei Shaoyi ◽  
Li Bo ◽  
Zhu Yanyan
Keyword(s):  
Lateral Force ◽  
Longitudinal Force ◽  
Lateral Acceleration ◽  
Stable Range ◽  
The Road ◽  
Nonlinear Compensation ◽  
The Stability ◽  
Standard Calculation ◽  
Double Nonlinear ◽  
Brush Model

On the basis of calculating the longitudinal force using the original brush model, we simplify the tire structure and consider the lateral force generated by the lateral elasticity of the tread. At the same time, the boundary conditions between the adhesion area and the slip zone in the contact area of the tire are fully discussed. By establishing an improved tire brush model, the error caused by neglecting the sideslip characteristics is avoided, and the adaptability of the tire model is improved. A double nonlinear compensation method based on the lateral acceleration deviation and the yaw rate deviation is employed to estimate the road adhesion coefficient, which is closer to the actual attachment situation than the standard calculation. Based on this model, the vehicle stability coefficient k is defined and calculated to describe the stability of the vehicle during the driving process. The modeling results show that the value of k is always in the stable range of [0, 1]. Therefore, the vehicle that utilizes the improved tire brush model is always within the controllable range in the driving process, which verifies the effectiveness of the model.

Diffusion study of chloride and binding of water in concrete pore by molecular dynamics simulation using LAMMPS

2021 ◽  
Vol 12 (3) ◽  
pp. 88
Author(s):  
Md. Shafiqul Islam ◽  
Sayem Ahmeed ◽  
Sumon Kumar Ghosh
Keyword(s):  
Diffusion Coefficient ◽  
Chloride Ion ◽  
System Size ◽  
Dynamics Simulation ◽  
Chloride Diffusion ◽  
Water Molecules ◽  
Chloride Diffusion Coefficient ◽  
Average Value ◽  
Temperature And Pressure ◽  
Different Characteristics

As for the communication between concrete and the particles, the surface shows Cl− shock and Na adsorption. With expanded particle focus, the solid adsorption capacity for Cl− is upgraded as a result of a detailed overview of the dynamic molecular simulation studies examining the chloride diffusion coefficient. Different characteristics of the diffusion process, including molecular models, system-size effects, temperature, and pressure conditions, and the type of protection, are discussed. This paper focus on Molecular Dynamic Simulation to determine the diffusion coefficient of chloride ion and water molecules in concrete. The diffusion coefficient for NaCl salt obtained 6.60178x10-10m2/s and the diffusion coefficient for CaCl2 salt obtained 7.29305x10-10m2/s. So, the average chloride diffusion coefficient 6.9475x10-10m2/s. Diffusion coefficient obtained from graph 5.562x10-10m2/s. Diffusion coefficients for water molecules for NaCl solution are 6.125x10-10m2/s, 6.85x10-10m2/s, 1.044x10-10m2/s, 8.525x10-10m2/s, 6.25x10-10m2/s. diffusion coefficient of water molecules in CaCl2 solution are 4.5x10-10m2/s, 6.725x10-10m2/s, 1.254x10-10m2/s, 7.725x10-10m2/s, 1.3x10-10m2/s. Average value obtained for water molecule diffusion are 4.545x10-10m2/s, 7.4062x10-10m2/s and 1.149x10-10m2/s. This diffusion of chloride effects the binding of water in concrete pore.

scholarly journals Sliding Mode Control of Laterally Interconnected Air Suspensions

2020 ◽  
Vol 10 (12) ◽  
pp. 4320 ◽  
Author(s):  
Dou Guowei ◽  
Yu Wenhao ◽  
Li Zhongxing ◽  
Amir Khajepour ◽  
Tan Senqi
Keyword(s):  
Ride Comfort ◽  
Control Method ◽  
Sliding Mode ◽  
Suspension System ◽  
Lateral Acceleration ◽  
Sliding Mode Controller ◽  
The Road ◽  
Air Suspension ◽  
Simulation Based ◽  
Different Levels

This paper presents a control method based the lateral interconnected air suspension system, in order to improve the road handling of vehicles. A seven-DOF (Degree of freedom) full-vehicle model has been developed, which considers the features of the interconnected air suspension system, for example, the modeling of the interconnected pipelines and valves by considering the throttling and hysteresis effects. On the basis of the well-developed model, a sliding mode controller has been designed, with a focus on constraining and minimizing the roll motion of the sprung mass caused by the road excitations or lateral acceleration of the vehicle. Moreover, reasonable road excitations have been generated for the simulation based on the coherence of right and left parts of the road. Afterwards, different simulations have been done by applying both bumpy and random road excitations with different levels of roughness and varying vehicle lateral accelerations. The simulation results indicate that the interconnected air suspension without control can improve the ride comfort, but worsen the road handling performance in many cases. However, by applying the proposed sliding mode controller, the road handling of the sprung mass can be improved by 20% to 85% compared with the interconnected or non-interconnected mode at a little cost of comfort.

The Nano-Cutting Mechanism Research of Polysilicon Based on Molecular Dynamics

2013 ◽  
Vol 690-693 ◽  
pp. 2559-2562
Author(s):  
Ying Zhu ◽  
Shun He Qi ◽  
Zhi Xiang ◽  
Ling Ling Xie
Keyword(s):  
Molecular Dynamics ◽  
Potential Energy ◽  
Cutting Force ◽  
Cutting Process ◽  
Dynamics Simulation ◽  
Cutting Mechanism ◽  
Nanometric Cutting ◽  
Mechanism Research ◽  
Atom Position ◽  
Dynamics Method

Molecular dynamics model of the polysilicon material under the micro/nanoscale is established by using molecular dynamics method, make variety of the typical defects distribute to the polysilicon model reasonable and relax the simulation model, obtain the system potential energy curves in the relaxation process and the atomic location figure after the relaxation. Conduct molecular dynamics simulation of nanometric cutting process relying on the development of simulation program, get instant atom position image and draw the cutting force curve. Discusses the typical defects impact on the polycrystalline silicon nanometric cutting process, those mainly include cutting force changes in the cutting process, potential energy changes and processed surface quality etc.

New Sliding Mode Controller for Robotic Manipulator Subjected to Disturbance and Uncertainty

2006 ◽  
Vol 220 (6) ◽  
pp. 807-815 ◽  
Author(s):  
J H Ham ◽  
S B Choi
Keyword(s):  
Position Control ◽  
Sliding Mode ◽  
Estimation Error ◽  
Sampling Period ◽  
Robotic Manipulator ◽  
Sliding Mode Controller ◽  
Control Performance ◽  
Parameter Uncertainties ◽  
Average Value ◽  
Predicted Values

This article presents a new sliding mode controller (SMC) for the position control of a robotic manipulator subjected to perturbations, such as parameter uncertainties and extraneous disturbances. The SMC is designed so that the sliding mode condition is satisfied and integrated with the perturbation estimator. The estimator is formulated by adopting a concept of the integrated average value of the imposed perturbation over a certain sampling period and realized using the Taylor series. In the formulation of the estimator, the relationship between control performance and sensor performance is established by adjusting the sampling ratio. Subsequently, in order to improve control performance, the actuating condition for the estimator is introduced: on-off switching condition (OSC). This condition is decided on the basis of the estimation error between actual and predicted values. By imposing the OSC, control accuracy can be enhanced when high frequency perturbations exist in the system. The benefits of the proposed methodology are demonstrated on a two-link planar manipulator. The position control performances of the manipulator are evaluated and compared between the proposed methodology and conventional control schemes.

Sign in / Sign up

Export Citation Format

Share Document